The present invention relates to an image forming method and an image forming apparatus, each for forming an image in such a manner that plural kinds of recording materials (such as coloring material, dyestuff, pigment, color ink, etc.), belonging to a same color category but being different in density, are emitted and distributed onto/over a recording medium by a plurality of recording elements, respectively, so as to form dots representing the image to be printed on the recording medium.
In the ink-jet printer or the like, an image is formed on a recording paper sheet (recording medium) by emitting ink droplets (recording materials) from a plurality of nozzles (included in the recording elements) In this case, an ink clogging failure is liable to occur, and accordingly, a white line is generated in the image to be formed on the recording paper sheet, due to an influence of a nozzle suffered by this ink clogging failure (a defective nozzle).
In order to eliminate the white line caused by the ink clogging failure, various kinds of methods have been considered and proposed so far. For instance, Tokkaihei 2-22066, Tokkai 2002-67297 (both Japanese Non-Examined Patent Publication), etc., have set forth various kinds of countermeasures to cope with the abovementioned failure.
Concretely speaking, Tokkaihei 2-22066 sets forth a method for detecting a defective nozzle that is incapable of emitting ink, and for eliminating the white line by employing an interpolating nozzle that corresponds to the defective nozzle. Further, Tokkai 2002-67297 sets forth a method for arranging interpolating nozzles in the vicinity of the defective nozzle that is incapable of emitting ink so as to interpolate the white line with the ink belonging to the color category same as that of the non-emission nozzle but being different in density, another method for emitting transparent ink from the interpolating nozzle, etc.
However, in every one of abovementioned methods, it is necessary to accurately locate the defective position at which the corresponding nozzle is incapable of emitting ink, and then, it is necessary to accurately position the interpolating nozzle at the defective position, so as to accurately conduct the ink emitting operation for interpolating the defect at a predetermined accuracy.
Therefore, there has been such a shortcoming that the ink emitting operation to be conducted at the defective position should be implemented at an accuracy being same as a nozzle arranging resolution (a number of nozzles for every unit length), resulting in a high accurate operating demand. To cope with such the shortcoming, there have been arisen various kinds of problems, such as a cost increase for increasing the resolution of the detecting section, an increase of arithmetic calculating load, etc.